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J. F. STIRSKY,

BURGLAR ALARM.

No. 511,370. Patented Dec. 26, 1893';

WITNESSES:

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NITED STATES:

PATENT OFFICE.

J OSEPH'F. STIRSKY, OF NELSON, CANADA.

BURGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 511,370, dated December 26, 1893. Applioation filed February 23, 1893. Serial no. 463,498. (No model.)

To all whom it may camera Be it known that I, JOSEPH F. STIRSKY, of Nelson, in the Province of British Columbia and Dominion of Canada, have invented a new and Improved Burglar-Alarm, of which .the following is a full, clear, and exact description.

My invention relates to an improvement in burglar alarms, and it has for its object to provide a device simple, (1 urable and economic in construction, and capable of being expeditiously and conveniently applied either to a window or to a door in such manner that when the window or door is opened, or when an attempt is made to open such door or window, an alarm will be immediately sounded by the device.

The invention consists in the novel construction and combination of the several parts, as will be hereinafter fully set forth and pointed out in the claims.

Reference is to be had to the accompanying drawings forming a part of this specification, in which similar figures and letters of reference indicate corresponding parts in all the views.

Figure 1 is a perspective view of the alarm, illustrating its application to a door. Fig. 2 is a front elevation of the alarm. Fig. 3 is a side View thereof, a portion being in section; and Fig. 4 is a transverse horizontal section taken practically on the line 4-4 of Fig. 2.

In carrying out theinvention a body or casing A, is provided, of any desired shape and of any approved material. The casing is closed at the front and sides but ordinarily is left open at the back, although the back may be closed also if in practice it is found desirable. At each side of the casing a rod is secured, the rods being designated as 10 and 11. These rods extend beyond the top and bottom of the casing, and the upper ends of the rods 10 and 11, are pointed while theirlower ends are connected by a cross bar 12. A yoke 13, is held to slide upon both the side bars 10 and 11, the said yoke comprising preferably two apertured disks 14, forming the sides, each set of disks having sliding movement upon one of the rods 10 and 11, and two or more cross bars, preferably two, designated as 15 and 16 and shown best in Fig. 2,the said cross bars connecting transversely opposingdisks;

and the yoke is adapted to carry two feet 17, which are usually secured to the sides of the disks and extend downward below the cross bar 12 connecting the rods 10 and 11. The feet 17, are usually made pointed or otherwise sharpened at their lower ends, and the pointed ends of the feet are kept below the main cross bar 12 by means of springs 18, which are coiled around the upright rods 10 and 11, bearing against the yoke at one of their ends, and bearing at their opposite ends against collars 19, formed upon the rods. Thus when pressure is exerted upon the upper ends of the rods 10 and 11 and downwardly upon the casing, the yoke, when the feet 17 rest against a support, will be forced upward on the lower ends of the rods and will compress the springs 18.

Two gongs 20 and 21, are located upon the front face'of the casing A, one above the other at a suitable distance apart; and between the two gongs a post or arbor 22, is located, which extends within the casing and beyond its outer or front face. The arbor near its outer end is provided with a crank arm 23, rigidly attached to it; and a tongue 24, is pivotally connected with the outer end of the crank arm, as shown in both Figs. 2 and 3, while upon the extreme outer end of the post or arbor a finger 25, is rigidly secured,turning with the arbor, and this finger is usually bent over the crank arm and then outward and in direction of oueside of the casing.

The arbor is geared with any approved clock mechanism B, located within the casing, the drive wheel of the clock mechanism, designated as 26, being connected with the post or pinion 22 by means of a small gear 27. The post or pinion 22, is so located that when it revolves the tongue 24. will be thrown laterally in engagement with each gong 20 and 21, thus sounding a continuous alarm; but when the clock mechanism has been wound up the post or pinion is prevented from revolving by means of a trip arm 28 engagingvwith the finger 25 of the post, as shown also in Figs. 2 and 3, the upper end of the trip arm being curved in a manner to engage with the finger, while the body of the arm is carried downward through suitable guides attached to the outer face of the casing to a permanent attachment with the yoke 13. Thus in operation it will be observed that when the spring of the clock mechanism has been properly wound, as long as the springs 18 on the device force downward the yoke 13 and keep it in its normal position, the trip arm will prevent the post 22 from revolving by engaging with the finger 25 of that post; but when the feet 17 of the device are forced in the floor, as shown in Fig. 1, and the upper pointed ends of the arms 10 and 11, are brought to a firm engagement with the door, for example, if an attempt is made to open the door the arms 10 and 11 will be pressed downward, and the trip arm 28 will thereby be carried out of engagement with the finger 25, and the post will at that time revolve and the tongue will sound an alarm by engagement with the gongs 20 and 21. It is evident that the device may be applied in like manner as shown in the drawings to a window or other place where an alarm is to be sounded when an entrance is attempted.

The device is exceedingly simple, it is economic and durable in its construction, and it is capable of being expeditiously and conveniently applied by any one of ordinary intelligence.

Having thus described my invention, 1 claim as new and desire to secure by Letters Patent- 1. A burglar alarm comprising a casin g provided with parallel rods projecting at their ends beyond both ends of the casing, the upper ends of the rods being pointed,'spring propelled gearing within the casing, a transverse shaft driven from said gearing and provided at the outer side of the casing with a crank arm having a hammer pivoted thereon, a transverse finger also on the outer end of the shaft, a gong in the path of the hammer, spiral springs on the lower ends of said rods, a yoke sliding on the said lower ends against the action of said springs and provided with spurs and a trip arm extending upwardly from the yoke and having alaterally projecting upper end engaging the said finger, substantially as set forth.

2. A burglar alarm comprising a casing provided at its upper end with penetrating points, a sliding yoke at the lower end of the casing also having penetrating points and provided with a trip arm having a laterally projecting end, two gongs on the casing, a shaft journaled in the casing and projecting at its outer end through the casing between the two gongs and there provided with a lateral finger to engage the bent end of the trip arm and also having a crank arm provided with a pivoted freely swinging hammer to strike the gongs alternately when the trip arm releases the finger, and spring actuated gearing for driving the said shaft, substantially as set forth.

JOSEPH F. STIRSKY.

\Vitnesses:

S. P. TUCK, 0. S. F. HAMBER. 

